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No pressure

I’m on a campus with most buildings running on two pipe systems that used to be vacuum. We can’t get the steam to move through the system. By the condensate receiver, we have steam returning from the other return lines. I figured the steam shut the trap off from the discharge but when I opened the strainer before, nothing. The receiver is at the lowest point in the system. Several buildings with similar issues. I can really use some insight.

Comments

  • Grallert
    Grallert Member Posts: 540
    I'm not sure if this is helpful but I have a similar issue with a building that was originally a vacuum system in the twenties and is now connected to a two pipe gravity from the fifties. I found that lowering the pressure to solved a ton of issues all over. Seems obvious to me now but it took a bet to get there. Just a thought.
  • bigpete638
    bigpete638 Member Posts: 74
    It turned out the danfoss valves we installed were not letting heat through. Not sure if the heads are compatible with the body. We had the body of the valves and just assumed the heads fit.
  • Grallert
    Grallert Member Posts: 540
    they look right but I'm no Danfoss expert, we use Macon. Does the steam pass with the thermostat off?
  • bigpete638
    bigpete638 Member Posts: 74
    I’m not getting notifications when responses come in. Sorry for not responding.

    The new heads were not allowing steam through. I spoke to the engineers about lowering boiler pressure but it falls on deaf ears. There are several buildings on campus that were converted from vacuum systems to gravity.
  • Grallert
    Grallert Member Posts: 540
    If you remove the head will steam pass through the valve?
  • ctkay
    ctkay Member Posts: 7
    Change the Danfoss heads to heads with the remote sensor, place the sensor in the air flow below the convector. As the valves are installed the thermostatic head is in the air flow, when the radiator temp goes up the head closes the valve. Most trv actuators are high limit of 86 deg.
  • mattmia2
    mattmia2 Member Posts: 7,172
    Isn't there something about how you have to position the valve before you install the actuator? I assume you read the instructions, but I am not an expert on this by any stretch, just sort of remember something I saw in some instructions about installing an actuator while looking for something else.
  • ctkay
    ctkay Member Posts: 7
    You can change the valve to 1 that has the actuator horizontal and use the actuator you have, tho it is easier to just change the type of actuator to the remote type, no piping involved then.